@misc{cryptoeprint:2004:359,
author = {Eike Kiltz and Gregor Leander and John Malone-Lee},
title = {Secure Computation of the Mean and Related Statistics},
howpublished = {Cryptology ePrint Archive, Report 2004/359},
year = {2004},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.